Blagaj is a village below a cliff, and the cliff is the whole story. The Buna river bursts out of a cave at the base of a sheer limestone wall about a dozen kilometres south-east of Mostar, one of the largest karst springs in Europe, and beside the cave stands a small tekke, a dervish monastery, built in Ottoman times. The white walls and the timber upper floor of the building seem to lean out of the rock, and the pale green water below moves quickly and silently. Above, on a ridge, are the ruins of a medieval fortress called Stjepan Grad, associated with the Herzegovinian nobleman Stjepan Vukčić Kosača, from whose title 'herceg' the name Herzegovina is said to come.
The approach by bike is a short, easy ride from Mostar, along a valley that gradually narrows. The roads here are not wild, but the setting makes up for it. Heat shimmers on the road in summer, the air smells of dust and fig leaves, and as you come closer you feel the temperature drop as the cold river air meets you. Parking is tight near the spring, and the little lane is crowded with tourist coaches from Mostar in the middle of the day, so arrive early in the morning or later in the afternoon to enjoy it properly.
Beside the river there are cafés and small restaurants with terraces right over the water, which is an excellent place to sit for an hour with a coffee and the sound of the Buna. Trout is a common speciality here, as the water is clear and cold all year, and you will often see it on menus. The tekke can be visited, with a modest entry fee, and visitors are asked to dress respectfully and remove their shoes inside.
Blagaj itself is small, and the nearest larger place with a full range of services is Mostar, about eleven kilometres away. Fill the tank there before riding out. After you have finished here, consider continuing south along the valley toward Stolac, where the landscape stays dry and stony and the riding is relaxed, or loop back north to the bridge and the old town of Mostar.