Today the main entrance is through the old south bastion which has been reconstructed using sections of wall arranged in a circle.
At the end of the 13th century renovation work was carried out on the castle under the direction of Otto the Strict.
As the village of Gifhorn developed, the importance of the castle grew, both for security reasons and as a customs post on a trade route.
In 1396 Duke Frederick transferred the castle to his wife Anna of Saxony as a life annuity.
The present structure was built from 1525 as a completely new castle, not on the site of its predecessor, but on a hill on what was then the northern edge of the town of Gifhorn.
Ernest gave the castle as a wedding present to his wife, Sophie of Mecklenburg-Schwerin, on the occasion of their marriage in 1528.
On taking over the castle in 1539, Duke Francis was able to indulge his noble image of himself and attended to his princely representational duties unfettered.
Life with his more prudent brother, Ernest and the relatively modest standard of living in the small Celle Residenz was not enough for him.
Nevertheless the castle was retained as a fortress, because it had a strategically important function for the Celle dukes on the southeastern flank of their dukedom.
The last Schlosshauptmann, Ulrich von Veltheim allowed the fortifications to be dismantled between 1770 and 1780, because it was no longer equal to technological advances of that time.