I'm including Mirissa and Weligama in one post because they are within walking distance to one another. We stayed in the middle and spent 2 days in each town.
The beach here is a small crescent that is absolutely picture perfect, there's a small island on one end that you can walk to (you will get wet) which has a seat on the top, a perfect place to watch the sunset, and the other end of the beach is capped with a green cliff face which would look great on any post card.
There are a few cafes built right onto the sand (like Unawatuna but not as overly developed), and the whole place has a laid back vibe.
The harbour in Mirissa is colourful and busy, certainly worth a quick detour.
Mirissa is famous for its whale watching tours, but we visited during low season and were told that there would be no tours during July and August because the sea was too rough.
A surfers paradise, the beach here goes on forever. We walked about 25 minutes before seeing another human being, there was nothing on the beach other than the odd fishing boat and a few surfboard rental huts.
Once you leave the Beach and cross the road, Weligama is a bit more developed that Mrissa, with more selection of restaurants and a supermarket.
There is a small but impressive statue in Weligama, it's alleged to be over 1,500 years old. It's called the Kushtarajagala statue and is just after the railways tracks on Matara road.
Overall Weligama was our favourite out of the two, the beach was less crowded and we had our best curry in Sri Lanka at Akila Kitchen, it's number 1 position on TripAdvisor is truly deserved.
Where To Stay:
We stayed at the Latheena Resort, Weligama was about a 20 minute walk west and Mirissa was about 30 minutes east. The hotel backed onto the beach.
Breakfast was good and was included in the price. The family who ran the hotel were great and their kids were adorable. We got laundry done for Rs50/item, smaller items were free.
I would certainly stay here again.
How To Get There:
If coming from Galle or Unawatuna, take any bus headed for Matara, and if coming from Matara, take the bus to Galle. A tuk-tuk will cost around Rs1,200. The train services are infrequent.