Tassamaharma is a city in Sri Lanka.
Tissa is a gateway to Yala National Park. It is a charming village with lots of scenery and some ancient archaeological ruins.
Sri Lankan Airlines canceled flights to Mattala since Jan 2015 until the moment of writing this text Dec 2015
There are no trains that come out here yet.
There are regular buses from most major cities in the south. Expect about a 4-5 hour journey if coming from Galle. Busses coming from the north, unless they are direct, will drop you at the Panigamo Junction. From there, a tuk-tuk to town costs around 200/300 LKR to town/your hotel. At the junction, there are several touts for hotel and safari combinations; some aren't a bad deal, so long as you know what you want and can bargain hard.
It is mostly walkable. You may also take local buses with the help of friendly villagers. As normal in Sri Lanka, a tuk-tuk is never far away.
Take a walk around Lake Tissa and the surrounding wet lands. It is full of all sorts of wild life. There are small dirt roads that take you through farm fields and modest homes. It is a great way to see how real Sri Lankans live. Along the main lake, there are often locals fishing with cane poles. Right behind them another person is breading and frying these tasty morsel to sell to anyone passing by. Stay out of the water though as crocodiles are masters of camouflage. When the weather is good, it is a great way to pass the time, while waiting for others to join your safari party or is a budget way to taste the tip of what Yala National Park has to offer.
Busses run into/out of Tissa along Kateragama Road and they can be flagged down from any point. Busses to Colombo pass by hourly for most of the day. The journey from Tissa to Colombo takes 8 hours and costs 460 LKR. It travels along Rout 2 and makes stops in all the major towns (you can ask to be let off at any point). The bus from Tissa stops in Tangalle (2 hours), Matara (3 hours), Galle (4 hours), Hikkaduwa (4.5 hours), etc. If you are staying at a hotel in south Colombo, you can ask the driver to drop you off along Galle Road (it helps if you know exactly where you are going or have a hotel card to show him), otherwise the bus continues to the main bus terminal.
If you are going north, you can catch the bus from the Panigamo Junction about 5 km from town (a tuk-tuk is 200-300 LKR). Busses to Ella take 3-4 hours, via Wellawaya. If you are going to Kandy you must change in Wellawaya and again in Badulla.