Great example of the time-travel land buying principle CG, is the richest man in England (or has been, if not currently), Gerald Grosvenor (Duke of Westminster).
An ancestor of his, married a girl whose father was a farmer outside London, and became the owner of a large field used for grazing livestock. It was the field on which the villagers held their annual fair to celebrate May day, and hence was known locally as Mayfair.
London, of course, expanded until it included this area (and several hundred square miles more), and if you know your Monopoly board game (UK edition), you'll know what the most expensive property on the board is called.
The ancestor was cunning enough only to sell houses built on the land with a 99 year lease, so every century since then they've been able to sell the most expensive real estate in GB all over again and make even more money (until the law changed in 1965, to give the tenants the right to buy the freehold)