Kalamata is a vibrant, bustling city at the top of the Messinian Bay which is famous for its excellent olives and not so excellent cigarettes but not much else, it does however merit an extended visit. The long beach on the bay is busy but not unpleasant and has a couple of enormous floating inflatables that look great fun for the kids. Heading inland there are plenty of shops, boutiques and restaurants in both the new town and old town. There is also an excellent indoor/outdoor food market on wednesdays and saturdays which I would recommend.
Kalamata was devastated by an earthquake in 1986, there were some fatalities and many old buildings were lost as a result. However, the old town is attractive and the newer lower town has large, airy streets and a huge modern square which are worth exploring.
You could go for the day, visit the market, have lunch, then visit the castle and the Archeological Museum of Messinia, then head home, a perfect day out. Parking by Ipapantis Church is free.
We wanted to taste a bit more of Kalamata than just a day trip so we stayed the night in the summer of 2019 and really enjoyed the experience. We stayed at the rather eccentric and cosy Kalamata Art Hotel centrally located on the large Aristomenous Square. Why eccentric ? Well just take a look at the open plan bathroom! We also liked the snazzy lift.