Visitors to Réunion don't have to confine themselves to exploring the surface of its volcanic formations – at Le Grand Brûlé, it's possible to go caving inside volcanic tubes (elongated tunnels formed by the cooling and rapid hardening of lava) and walk under the volcano.
A number of operators organise guided excursions through the lava tubes at Le Grand Brûlé. The tunnels are generally quite tall (and there are some openings in the ceilings, which allows for superb plays of light), but be prepared to stoop or squeeze at times. Another plus is that it’s suitable for all ages – bring the kids (aged 8 and over)! All you need is good shoes; torches and helmets are provided.
Prices vary between €50 and €75, depending on the length and duration of the circuit.