Buitrago del Lozoya is the Comunidad's best medieval surprise: the only town in the region that keeps its full circuit of walls — 11th-century Moorish masonry patched by Castile — wrapped on three sides by the green moat of the Lozoya river. Inside: a castle, a Mudéjar church tower, lanes that empty by dusk; and, improbably, a Picasso museum built on the collection the artist gave his Buitrago-born barber, Eugenio Arias.
It sits on the A-1 an hour north of Madrid, the natural gateway to the Sierra Norte's black-slate villages and the Sierra del Rincón biosphere reserve. Beds are few and honest; summer brings a medieval festival and river-beach afternoons, winter the smell of woodsmoke over the battlements.
Walls, bridge & the Lozoya bend — 4 km · 1.5 h. Puerta del Piloncillo → full adarve wall circuit → down to the old bridge → the riverside path around the meander for the classic across-the-water view of the whole walled town. Short, and entirely photogenic.
Bus 191 from Plaza de Castilla (~1 h 15, roughly hourly). Drivers take the A-1 to exit 74 (55 min) — the same road continues to the Hayedo de Montejo and the Sierra del Rincón villages. No rail.
Inside the walls if you can — a handful of small lodgings put the wall-walk and castle at your doorstep. The new town across the bridge has the practical hostals and bar life. For silence, casas rurales in the hamlets up the valley are minutes away.
Buitrago del Lozoya lists around 10 bookable hotels and guesthouses, from roughly €44/night. Prices on the area page are live; booking 3–6 weeks out usually lands the best rate, with free cancellation on most rooms.
Curated picks are coming — meanwhile, the live search covers every bookable property at the same price or better.