Four London hotels, each within 0.2 km in a straight line of a tube station. What sets them apart is the clock on the casino floor and the formalities at its door.
Berkeley Square in Mayfair on a winter morning
Two never close. Grosvenor Casino The Park Tower, inside the Knightsbridge hotel, and Grosvenor Casino Gloucester Road, inside the Millennium in South Kensington, open and deal around the clock. Grosvenor Casino St Giles, which STG Hotel Oxford Street calls next door, is open 24 hours and deals from noon to 6am. The Palm Beach, in the May Fair Hotel's former ballroom, opens noon to 6am, tables from 1pm.
Entry differs too. The three Grosvenor rooms ask for a free one-time sign-in with photo ID on your first visit; after that you walk in. The Palm Beach registers every guest at its desk before entry, and you go in from Berkeley Street. Knightsbridge, Gloucester Road and Green Park stations are each 0.1 km off in a straight line, Tottenham Court Road 0.2 km.