His course handbook gradually thickened into something he could sell as an all-purpose guide to Europe, and before long he was running itineraryless minibus tours through the continent, putting up paying customers of all ages in hostels, empty bomb shelters and a 50-cents-a-night communal tent in the Munich Botanical Gardens.
Lisi had long fantasized about opening a "science hostel," a big empty house in a beautiful place, like Tahoe, where scientists would gather to do research.
In 1896 the family bought a former palace of a pasha, which had been empty, and turned it into a hostel for pilgrims.
Cramped but colorful sleeping quarters are the focus of another series, "Empty Beds," shot in men's hostels around Durban while the occupants were working or traveling.
But an empty apartment or group of apartments cannot be turned into makeshift hostels.
"There is strong evidence that far from simply facilitating the use of empty spare rooms, Airbnb actually enables landlords to bypass government regulation and in effect run illegal hostels," Julian Ledger, chief executive of YHA Australia, told a parliamentary inquiry.
Tucan Travel (020-8896 1600, tucantravel.com) has a 13-night trip for £730pp, including B&B accommodation in hotels, hostels and guesthouses but excluding flights March average high: 26C If the nest is empty, mum and dad could head to Central America and make a difference working with children and staff at adoption homes and care centres in and around San Ramón.
Up the coast, Figueira da Foz isn't the prettiest resort but the waves are empty even in summer, there are several beaches (and one of Europe's longest right hand breaks) and a great hostel – Foz Holidays Surf House (fozholidays.com, €25 B&B per night).
