The Inland Sea, about 80 km south of Doha near the Saudi border, is a tidal inlet that cuts into the heart of a spectacular dune landscape. Getting there requires a 4WD and is most easily done via an organised desert safari — the last section involves driving over large sand dunes, which requires deflated tyres and some confidence on the wheel.
Most visitors combine the drive with dune-bashing, sandboarding, and a stop at the waterside. Overnight camping is possible and gives you the desert at dawn, which is a different experience from the day-tripper rush. Several tour operators in Doha offer half-day and full-day trips; prices are reasonable. The best time is October to March.