Seethawaka Botanic Garden is a Wet Zone Botanic garden covering 79 acres (32.00 ha), which mainly serves as a research area and a conservation area for threatened and vulnerable endemic plant species in the Sinharaja Rain Forest region.

The garden was opened to the public in late October 2014 and it the most recently constructed botanical garden in Sri Lanka. It also aims to promote the improvement of export floriculture, ex-situ conservation of wet lowland plants, and bamboo cultivation. It is located on the Puwakpitiya-Thummodara main road, at Illukowita, adjacent to the IndikadaMukalana Forest Reserve at Avissawella. Seethawaka Park is open all the days throughout the year from 8.00 am to 5.00 pm.

Unlike most conventional botanical gardens in the country, Seethawaka wet zone botanic gardens predominantly consists of plants rather than flowers. The rationale behind the launch of this park is to establish a center to conserve the highly threatened wet lowland forest flora for future generations, and therefore consists of many lesser known and endangered wet zone plants of sri Lanka. A beautiful stream flows through the garden, which sustains the existence of various wet zone plants. The park has a cool temperature, mainly due to the ample Kumbuk foliage throughout the garden.

Visitors can also enjoy a boat ride at the man make lake built using the natural water flow from the nearby hills. Nicely paved path directs to the summit of the park at which visitors can relax bit and observe the garden below and the mountainous surrounding. Most of the trees and plants are marked with a name tag for the visitors to identify them. Seethawaka Botanical Garden still growing. Some are recently planted trees and they need some time to grow and show their real beauty.