Bingling Si (Thousand Buddha Caves) is 70 km southwest of Lanzhou and is the best reason to stop here. The Buddhist cave complex dates from the 5th century and was largely spared the Cultural Revolution's destruction — 183 grottoes cut into dramatic eroded cliffs above the Yellow River, with the 27-metre seated Maitreya Buddha (cave 172) as the centrepiece. Getting there requires taking a bus to Liujiaxia Dam and then a boat through the gorge, which is spectacular in itself. Allow a full day. Tours depart from Lanzhou's West Bus Station early morning; independent travel is possible but slower.
Labrang Monastery is 280 km south-west in Xiahe (Gannan Tibetan Autonomous Prefecture). One of the six great Gelug monasteries and the most accessible major Tibetan monastery in China, with over 2,000 monks, six academic institutes, and significant Buddhist cultural objects. The town of Xiahe itself is a fascinating mix of Tibetan, Hui, and Han culture. Requires an overnight stay.