CONNOR: Good thinking! I read a bit about limestone on the bus journey. Limestone is a sedimentary rock created by layers of skeletons and shells of sea creatures found in ancient, warm ...

Percé Rock is one of the largest natural arches in the world. It rises sheer from the Gulf of St. Lawrence in Quebec near the village of Percé. It is a massive limestone stack 433 metres ...

This austere stack of limestone-clad blocks ... the late Pei, knew what the legacy of this "big bang" meant for Doha's architectural landscape. Fearing the MIA would be crowded out by future ...