Head out to Tres Chimbadas, an oxbow lake created by the Rio Tambopata. It’s a prime spot for bird watching and for spotting giant river otters as they play in the shallow waters. You can also go piranha fishing. It’s catch-and-release only, but it’s great fun – just keep your fingers out of range of their perilously snapping teeth. Tres Chimbadas is slightly further from Puerto Maldonado than Lake Sandoval, but can still be visited as a day trip and has fewer tourists.