This is a closer photo of the lake in the crater of Irazu volcano, which I showed yesterday. The lake is yellowish green in color because of the sulfuric content of the water.
The crater is 1,050 meters (3,444 ft.) in diameter and 300 meters (984 ft.) deep. That makes it the largest crater in Costa Rica. Bring a jacket if you plan to visit, as it is cool at the high elevation, otherwise you will be scurrying back to your car if it becomes windy.
The crater is a short walk from a parking area, so this is a convenient volcano to visit. There are hiking trails to the four other craters in the park.