Welcome to Attapeu
This reputation is deserved, though quite ironic given that Attapeu actually means 'buffalo shit'. In the old local Mon-Khmer dialect, this area was called itkapu (ait krapeau in contemporary Khmer) because of the many wild buffalo living in the area. With some subsequent adjustment in pronunciation by the French, the town became Attapeu.
Despite any hope inspired by the greenery, the town itself is short on attractions, though the nearby temples at Saisettha and war junk in Pa-Am are interesting.
A Vietnamese phrasebook will be just as useful as a Lao dictionary since about half the population is Vietnamese.