In the early days, the Trust was concerned primarily with protecting open spaces and a variety of threatened buildings; its first property was Alfriston Clergy House and its first nature reserve was Wicken Fen. Its first archaeological monument was White Barrow. The focus on country houses and gardens, which now comprise the majority of its most visited properties, came about in the mid 20th century, when it was realised that the private owners of many of these properties were no longer able to afford to maintain them.