V, the tombstones of Muhammad II, Isma'il I, Yusuf I and Yusuf III were discovered. When Torres Balbás investigated the site in 1925-1926 he found 70 more graves inside the enclosure. Almost all the graves were already empty, as Muhammad XII, the last sultan of Granada, arranged to have the remains of his ancestors moved to an unknown site at Mondújar, in the Alpujarras. Generalife To the east of the Alhambra and outside its walls is the Generalife (from ), a Nasrid-era country estate which was first built by Muhammad II and Muhammad III in the late 13th and early 14th centuries. It underwent multiple modifications under later Nasrid rulers and then by Christian Spanish builders in the 16th century. It features several rectangular garden courtyards with decorated pavilions at either end. A large area of landscaped gardens from the 20th century occupies the approach to the former palace today. The Nasrid palace was originally linked to the Alhambra by a walled corridor that crossed the valley between them. Other outlying structures The main approach to the Alhambra today is through the Alhambra Woods in the valley on its south side. The outer entrance to the woods is through the Puerta de las Granadas ('Gate of the Pomegranates'), a formal Renaissance-style gate built in 1536 over the remains of an earlier Islamic-era gate. Within the woods is the Puerta de Birambla (from Arabic Bab al-Ramla), one of the former Islamic-era gates in Granada's city walls which was demolished between 1873 and 1884 and then reconstructed here in 1933. To the south of the Puerta de las Granadas are the Torres Bermejas ('Vermilion Towers'), a group of three adjacent towers on the Mauror Hill. Their origin is not clear, but the oldest remains found here date from the late 8th century or early 9th century. They may have been inhabited by Muhammad I (the founder of the Nasrid dynasty). In the 16th century, during the Christian Spanish era, an artillery bastion was added to them on the northwest side. During the Nasrid period there were several other country estates and palaces to the east of the Alhambra and the Generalife, located on the mountainside and taking advantage of the water supply system which ran through this area. The two best-known examples are the Palacio de los Alijares and the Dar al-'Arusa (), both of which were built in the 14th century