Here is a comprehensive tourist visitor guide to Kalamata, Messinia in Greece:

1. Introduction:
Kalamata is a beautiful coastal city in the Messinia region of Greece. Located on the Peloponnese peninsula, this city is known for its rich history, stunning beaches, and delicious local cuisine. As a visitor, you will find plenty of things to see and do here, from exploring ancient ruins to sampling local olive oil and wine.

2. Getting there:
The easiest way to reach Kalamata is by flying into Kalamata International Airport, which serves both domestic and international flights. You can also take a bus or drive from Athens, which takes approximately three and a half hours.

3. Best time to visit:
The best time to visit Kalamata is between May and October when the weather is pleasant and sunny. However, note that July and August can be very hot, so consider visiting in the shoulder season for a more comfortable experience.

4. Where to stay:
There are plenty of accommodations in Kalamata to suit all tastes and budgets. Whether you're looking for a luxurious beachfront hotel or a budget-friendly hostel, you will find an option that suits your needs. Some popular options are Hotel Ostria, Elite City Resort, and Pharae Palace Hotel.

5. What to see and do:
Kalamata has plenty of attractions to keep visitors busy, such as:

- Visit the ancient Messene archaeological site to see one of the best-preserved ancient Greek cities.
- Explore the Castle of Kalamata, a Byzantine fortress that dates back to the 13th century.
- Spend a day at the beautiful Voidokilia Beach, known for its crystal clear waters and sandy shores.
- Take a trip to the Kalamata Municipal Railway Park to learn about the city's railway history and see vintage locomotives.
- Visit the Kalamata Municipal Gallery to see works by Greek artists, including contemporary painters and sculptors.
- Take a tour of the Kalamata Olive Oil Museum to learn about the history and production of olive oil, which is a staple of the region.

6. Where to eat:
Kalamata is known for its delicious cuisine, so be sure to try some local specialties during your visit. Some popular restaurants and cafes are:

- Akti Taygetos, a seafood restaurant with stunning sea views and fresh catch of the day.
- Kostantis, a traditional taverna with a cozy atmosphere and homemade dishes.
- Mesogiako, a cozy eatery with a focus on fresh local ingredients and seasonal dishes.
- Piña Colada, a beachfront cafe serving cocktails, coffee, and light bites with sea views.

7. Final tips:
- Make sure to wear comfortable shoes, as many of Kalamata's attractions involve walking on uneven surfaces.
- Consider renting a car to explore the surrounding area at your own pace.
- Bring sunscreen and a hat, as the sun can be strong during the summer months.
- Learn a few Greek phrases to interact with locals and show your appreciation for their culture.

With this guide, you're all set to explore the beauty of Kalamata and have an unforgettable experience in Greece. Enjoy your trip!