Tourism in Greece is very important and contributes 18%  of the country GDP. The government and private enterprise regularly invest in making international tourism a relatively simple affair for the traveller (for example, some 51% of Greeks around Athens are rated to have some English language skills) with a high regard for the visitor's comfort and enjoyment, with an extensive focus on just getting a tourist entourage from one place to another effectively.
Each year the tourist season (heaviest May to September, though tourism flourishes all year) edges upward in total numbers of visitors such that records seem to be broken almost yearly for total number of arrivals, and 2018 is expected to bring an all-time high of 32 million people.
The economic crisis brought about a 26% contraction in the Greek economy between 2007 and 2013  resulting in extensive turmoil in employment, business and banking, and this hurt tourism somewhat, but another result was an even sharper focus on this renewable income maker for the country, and as the Greek finances have improved, so has an explosion of activity to expand the tourist trade.
The EURAIL system carries passengers into 31 different countries, and beginning in 2019 EURAIL include 53 islands by way of ferries, in particular Blue Star Ferries and Superfast, both part of the EURAIL system. The island pass system does not include the Greek mainland, which is a separate add-on that can be purchased for use with a EURAIL pass.
March 2019: Story at Orlando Sentinel about the expansion of the Disney cruise offerings to include Piraeus, Katakolon, Santorini, Mykonos and Crete.
Tourist tips for visiting Athens
Jan 23, 2019: This Anthony Grant piece at MSN Online is a down-to-earth description by this Athens resident of acclimating to Athens (and Greece).
Tips on eating authentic food and avoiding tourist-pricing, when to use the subway and when to find another method, and how to visit the islands to the best advantage (and avoiding an experience the writer describes as a "blur" from doing too much, too quickly). The writer's reasoning for the tips are explained (there's quite a few more than what's mentioned here) and in an easy to understand way. (And this cracked me up, referring to Santorini: "...plans are afoot to triple the size of its sardine can of an airport, but absent some major volcanic activity, Santorini won’t be getting bigger any time soon.")
Athens Survival Guide - There's nothing like this site, it is full of photos and the personal experiences of Matt Barrett over many decades in Greece.
Online etickets for archeological sites, etc. - etickets.tap.gr - managed by the Archaeological Resources and Exploitation Fund of the Ministry of Culture and Sports.
Advice, Tips and promotional pieces on Greece from the world of travel media
20 secrets of the Greek islands - UK Telegraph - A survey of 20 islands with a brief description, tips and highlights. Islands covered are: Corfu, Spetses, Andros and Tinos, Kimolos, Koufonisia, Ikaria, Kythnos, Lesvos, Meganisi, Amorgos, Hydra, Alonissos, Paxos and Antipaxos, Kefalonia, Crete, Mykonos and Delos, Andros, Antiparos, and of course Santorini
Santorini: More than just a pretty face - Chicago Tribune - It seems, at least in most photographs, that Santorini towns like Oia are nothing but white. The whitewash, while scenic today, was originally practical: White reflects the powerful heat of the sun. What's more, the lime that makes the whitewash is a good antiseptic -- villagers knew it would naturally disinfect the rainwater that was collected on rooftops. And I love the way the blue and white of the townscape seem inspired by the colors of the Greek flag.
Greece’s Corinth Canal: The Complete Guide - Trip Savvy - Travelers to Greece have three main options to see the Corinth Canal. First, cruise lines with small ships like Silversea Cruises, Crystal Cruises, and SeaDream Yacht Club transit the canal on eastern Mediterranean itineraries. Second, several private companies depart from Piraeus, the port of Athens, and offer a cruise through the canal. Finally, cruise ships with a day in Athens often offer a half-day shore excursion to the Corinth Canal for those who have visited Athens before.
Why nothing compares to Summer in Greece
- Greek City Times - Greece over Summer is pure magic and for anyone lucky enough to have experienced some time here over the months of June, July and August, would surely agree that every day in Greece over the warmer months feels like a non-stop celebration of life, love, food, sea, sun and good times!
The Old-World Charm of Folegandros, Greece, Awaits - Mansion Global - Life in Folegandros moves at a slower pace... With its wild landscape and relaxing atmosphere, Folegandros is among the most impressive islands of the Cyclades. There isn’t much here other than beautiful beaches and hiking trails, but that is what’s inherent to its draw.
Why Greece Should be on Every Traveler’s Bucket List - Lazy Penguins - The Greek mainland is often given a miss by tourists as most head straight to the islands. However, the idyllic charm of the mainland, the highlands, and its old cities hide some wonderful sites.
The timeless appeal of island hopping around Greece - Screeny - There are around two hundred Greek islands to visit and every one of them has something unique to offer. No other country in the world has scattered its treasures so abundantly around itself.
So far I’ve managed only about 30 of them, but this year I added three more to the tally by visiting the Sporades archipelago. Skiathos is easily reached – there are direct flights from Gatwick and Manchester – and makes for a good starting point. The island is famous for its superb beaches.
Why Greece Is Best Seen by Boat - Conde Nast - Our journey ended where it began, in Kos Town. Here, the ruins of the ancient agora (marketplace) stand next to the modern-day equivalent, where locals sell thyme honey and powdery loukoumi (the Greek version of Turkish Delight). Kos is an easy enough town to explore on foot, with its winding cobbled alleyways full of trinket shops, and town square where the medieval Phoros Gate is stocked with perfumed Aubrieta flowers. Visit the Tree of Hippocrates, where the Greek physician taught his pupils, then stop at Aegli Cafe, the island’s first women’s cooperative. Everything served here is made on the island, including fresh fennel seed biscotti and garlicky tzatziki.
A Tranquil Oasis in Greece - NYT - As a Greek-American who visits Greece frequently, I was a bit disheartened that the hotel did not pay greater homage to the country’s rich history and culture in its décor, music and even TV channels.
The Stunning Blue Caves of Zakynthos Island- Popsugar - The arches formed thousands of years ago through erosion. Their geological formations are noteworthy alone, but the name comes from the hue of the sea that reflects onto the cave walls. The largest cave, Kianoun, can be visited by boat, and many of the boats are available to tourists for rent. You can swim around the caves yourself...
Best places to visit in Greece on a Road Trip - Daves Travel - I love it when people ask me what are the best places to visit in Greece on a road trip. I always reply with ‘how long have you got'? And this answer applies to both how long it will take me to answer, and the length of the road trip the person has in mind. I like a challenge though, and so I have put two lists and four road trip itineraries together.
Tips If You’re Visiting Greece - Huffington Post - Most everything closes at noon for a few hours.
In Spain its called “siesta” and they have it in Greece too. In some of the more touristy areas you’ll find everything stays open but if your visit takes you off the beaten path they will most likely be closed in the afternoon. Make sure you make that trip to the market and get your errands done in the morning and spend your “siesta” down at the beach.
A Supreme holiday in Greece - UK Telegraph - Relax with a four-night stay at the marvellous Electra hotel, perfectly located on Ermou street, the city's central shopping hub, within easy reach of famous Monastiraki and historic Plaka districts.
How To Plan Your Trip To Greece - Lost Waldo - The first thing you want to do is plan how you are going to get there. When you take Greece tours, you will typically find that all transport costs are covered. If you are traveling on your own or with your family, you can pick out multiple ways to get there and then get around once you are in the country.
World's most beautiful street located in Greece - Neo Kosmos - The wining image submitted by freelance photographer Konstantinos Stamatelis, shows a narrow street in the village of Molyvos, lined with small shop fronts and a 'roof' covering formed by nature itself with the overgrowth of trees and flowers.
"You can take a dip into the clear blue waters surrounding Zakynthos Island in Greece where you'll find the famous Blue Caves.
The arches formed thousands of years ago through erosion. Their geological formations are noteworthy alone, but the name comes from the hue of the sea that reflects onto the cave walls. The largest cave, Kianoun, can be visited by boat, and many of the boats are available to tourists for rent. You can swim around the caves yourself, but exploring the formations that continue underwater should be limited to experienced swimmers and divers."
A Healthy Guide to Greece - Greece is - If you want purely Greek food, there are now a plethora of options for fresh, organic, gourmet and quality traditional products to choose from, from pasta and berries to rare cheeses and fish.
Island Hopping Around The Cyclades - Huffington Post - As for beaches, there is an endless choice and it’s also worth noting that every one on the island is rated as excellent quality according to the Ministry of Environment, energy and climate change. In addition, the neighbouring uninhabited island of Polyegos is known for it’s turquoise waters and is accessible via water taxi.
Top 7 Things To Do in Greece - Luxury Travel Magazine ...If you fall in love with this magnificent country, then why not make the move here permanently? Shopping around and seeing what could be whilst in town is a great way to get to the know the area you’re staying in and to see what your money could buy.
7 things you must do in Greece - UK Wanderlust Convinced that all Greek islands are swarming with tourists? Well, think again! With over 6,000 islands and islets, it’s easier to find one that matches your fantasies without the crowds. Anafi is Santoríni (just west) without the hussle or the hassle. Pserimos sits between between Kos and Kalymnos and offers white sand, green sea and a church clinging to a low cliff. Even on islands that get ‘busier’ in summer like Donoússa, (and we’re talking relatively here), it doesn’t take much to find a deserted beach or a welcoming tavern.
From party animals to families, Greece’s Cyclades have something for everyone - Euronews - A top destination for summer vacations, Greece is suffering from the geopolitical situation this year. But holidaymakers would be wrong to shun this haven of tranquility in Southern Europe as a fall in bookings has led many hotels to cut prices already. Anyone keen to snap up a bargain break can head to the Aegean Sea where Greece's Cyclades islands have something in store for all kinds of travelers.
Visit Greece: Ideal destination for winter vacations as well - You will enjoy the natural beauty of the mountainous areas with the numerous cloud–capped peaks and the wide network of signposted trails while you go hiking or mountaineering. If you love mountain biking, or you use a 4WD vehicle, you will discover many off-road routes that will lead you deep into the heart of Greek nature.