Leapfrogging is the idea that lower-income countries can skip older technologies and jump directly to modern ones. In telecommunications, many nations never built widespread copper landline networks and instead adopted mobile phones, which were cheaper to deploy across rural and remote areas. Our World in Data explores how this pattern played out across the world. Building wired networks requires digging and stringing cable to every home, while mobile networks use towers that can cover large areas quickly. The result is that many people gained phone access much faster than the old infrastructure would have allowed.

Hampi is a UNESCO World Heritage Site in Karnataka, India, with more than 1,600 surviving remains spread over 4,100 hectares. It was the capital of the Vijayanagara Empire from 1336 to 1565. Travellers from Persia and Portugal described it as a prosperous, wealthy and grand city with temples, markets and farms along the Tungabhadra River. By 1500 it was estimated to be the world's second-largest city after Beijing, and probably India's richest at the time. In 1565 a coalition of Muslim sultanates defeated the Vijayanagara Empire, its capital was conquered and destroyed, and the city was left in ruins. Hampi remains a religious centre, with the active Virupaksha Temple at its heart.