Arenillas is a municipality located in the province of Soria within the autonomous community of Castile and León in north-central Spain. It is situated in the Tierras de Berlanga district, positioned between the villages of Lumías and La Riba de Escalote, approximately 72 kilometres from the city of Soria.
Like many rural areas in Soria, Arenillas experienced significant population loss due to migration to Spanish cities starting in the 1960s. In response, a community association established in the 1980s initiated local revitalization efforts that earned the municipality a national community-development award in 1991. More recently, the town gained international attention for its initiative to attract residents by offering free housing and employment to craftspeople.