Manzanares is home to many highly-rated hotels, one of which is Parador de Manzanares, which has a current rating of 8.2. For other potential stays, consider Hotel El Cruce and Complejo Hotelero Saga, which can also be great places to stay in Manzanares.
A good hotel close to Manzanares Castle is Parador de Manzanares (rated 8.2/10 from 777 reviews).