As described in the famous novel by Bram Stoker, the castle was near the Borgo Pass. It was reached from Pasul Tihuts, a point near the summit of the crossing, on a road way leading south into the high mountains. The castle sat on a great rock overlooking the surrounding forest which was sliced by several rivers.
The castle was built so that attack was impossible. The large windows were placed above the level that arrows and other objects could not reach.
The most common place to look for the castle would be by the Borgo Pass and in fact there are two castles in that area. The first was built in the 13th century, by the 15th century most of the castle was removed, because of lack of use.
(Looking down from inside Castle Dracula)
Of the two castles that Dacula found, the Castle of Arges was in the more strategic position, possibly the major reason for his choice to rebuild it instead of settling at Poenari. It was located on a precipice overlooking the River Arges.
Vlad's Castle was quite small when compared to either Bran Castle or Hundoara. To the north were the mountains dividing Transylvania and Wallachia, and to the south, a commanding view of the countryside. There were three towers and walls thick enough to resist Turkish cannon fire, with room for 300 people. According to legend, a secret staircase led into the mountain to a tunnel, which in turn, led to a grotto that opened on the bank of the river below the castle.
The Turks attacked and captured the castle in 1462. Vlad escaped north through the mountains, but his castle was severly damaged. It was used by some of his successors as a mountain retreat but it was gradually abandoned.
In 1912 the towers of the castle still stood. On January 13 1913 an earthquake caused the main tower to fall into the river. A second earthquake in 1940 did further damage. In 1970 with a growing interest in Dracula, the Romanian government carried out a partial reconstruction and built a walkway up the mountain side to the entrance of the castle. Castle Dracula can be reached by car and a 45 min walk up the walkway to the entrance.
Source - Text and Picture