Tuonela Planitia
Voyager 2 image of Tuonela Planitia across the upper half, with Ruach Planitia below. Several "islands" occupy Tuonela Planitia's interior, with Kasu Patera at the upper right | |
| Feature type | Walled plain, cryolava lake |
|---|---|
| Location | Monad Regio, Triton |
| Coordinates | 34°00′N 14°30′E / 34.000°N 14.500°E |
| Depth | ~200 m |
| Dimensions | ~400 x 150 km |
| Discoverer | Voyager 2 |
| Eponym | Tuonela |
Tuonela Planitia is an elongated plain and probable cryolava lake on Neptune's moon Triton. Located in Triton's northern hemisphere within Monad Regio, it overlies part of Triton's unusual cantaloupe terrain. As with neighboring Ruach Planitia and the other walled plains on Triton, Tuonela Planitia is among the youngest features on Triton's surface.