Aden's sights are the legacy of its geography — a port wedged into an extinct volcano — and of layered occupation by Romans, Ottomans, Portuguese, and British. The Cisterns of Tawila are the oldest and strangest. The Crater district holds the Aidrus Mosque and the streets of British-era buildings. On the south coast, Sira Fortress and the Al-Maashiq Palace overlook the harbour. Conflict since 2015 has damaged or closed several monuments. Check on the ground before assuming anything is reachable or safe.