The Gateway of India is an arch-monument built during the 20th century in Mumbai. It was erected to commemorate the landing of King-Emperor George V and Queen-Mary at Apollo Bunder during their 1911 visit to India—the first time a British monarch had visited the country. The structure is a blend of Roman triumphal arch and 16th-century Indo-Saracenic architecture. Ironically, while it was built to welcome the British, it was also the symbolic exit point for the British Empire; in 1948, the last British troops to leave India marched through the gateway to their ships. The structure is made of yellow basalt and reinforced concrete, designed to withstand the salty air of the Mumbai harbor.