There are more than two dozen national parks in Sri Lanka, but the most famous of them is Yala. A lot of animals live on the area of 1,000 square kilometers. The most valuable find for a photographer is, of course, a leopard. Unfortunately, we didn't see it, but searched a lot:) Despite this fact the impression of the park is very positive.
To visit the park, you need to choose accommodation. The nearest village is Tissamaharama (hotels), you can also stay in the park in a bungalo (hotels). We stayed in Tissamaharama (22 km from the park) near the lake. A jeep took as from the hotel and brought back. It's not difficult to find a jeep in Tissamaharama.
The cost of visiting the park depends on the visit duration, comfort in the jeep and tips to the guide/driver. It will be about $50-60 to rent a jeep for all + ticket price of $30 per person. The number of animals seen totally depends on the guide/driver. In Tissamaharama or in the tourist center of the park you can find other travelers and share the cost of jeep rent. It is best to visit the park early in the morning or just before sunset, when the animals come to drink, and in the afternoon there is nothing to do. A trip in the park lasts at least 3-4 hours on a dirt road, so make sure that you will be comfortable in the jeep.
It is possible to go out of the jeep only in one place, near the memorial on the beach, which was devastated by tsunami in 2004. During the tsunami, the waves were up to 6 meters and slid deep into the park for 1.5 km, killing more than 200 people. It is interesting that the animals moved away from the coast before the tsunami. It was determined later by the analysis of tracks of elephants, which had GPS sensors on them.

The elephant obviously didn't like it, so it broke a small tree and ran after our jeep. ©Yuriy Buriak
Companies that organize safari tours in Yala:
http://www.yalasafaritours.blogspot.de/
http://srilankayalasafari.com/
http://www.yalahotel.com/yala_safari_tours_reservations.html
http://yalasafariholidays.com/jeep_safaris.html
http://www.yalawild.com/
http://www.aliyasafari.com/
Although, booking via the Internet is not necessary unless you want a specific jeep.
Getting there: Tissamaharama village is a reference point. From Colombo it is about 7 hours by car. Taxi cost starts from $150. You can take a direct bus that goes about 9 hours or with a change in Matara. There is a train from Colombo to Matara and bus from Matara to Tissamaharama that goes about 2 hours. There are day tours to Yala from the hotels on the south coast. A taxi from Mirissa or Unawatuna will cost $50-70. One more option is to come from the area of Ella/Nuwara Eliya (a bus runs from the town of Wellawaya).