No visitor to Newark can fail to be curious about the impressive remains of the medieval castle overlooking the River Trent.
Newark Castle is without doubt the most significant landmark in the town, although only 20% of the building still stands.
The majority of the castle we know today was built by Alexander the Magnificent, the Bishop of Lincoln and the Lord of the Manor of Newark in the early part of the12th Century.
Previous castles had existed on the site - the first likely to have been built by the Normans during the winter of1068-9.
The castle in existence at about 1130 was lavishly rebuilt and remodelled by Alexander.
He built the magnificent gatehouse, which is one of just two main sections of Alexander's castle that remain.
The three-storey gatehouse is the most complete example of a Romanesque gatehouse to survive in England.
It was designed to impress guests and reflect the wealth and power of the castle's owner.
Visitors would pass through its heavy wooden gates before emerging in the courtyard to be greeted by freestanding buildings such as a chapel and a kitchen.
Alexander also built at least one angle tower, the south-west tower, nicknamed King John's Tower, which is the other remaining section.
Despite its title there is no evidence to link the tower with the king, although he did die within the castle in 1216.
There were far better apartments that he could have occupied and it is probably a 19th Century invention that he died in the tower.
Short sections of the 12th Century curtain walls built by Alexander also remain - two on either side of the gatehouse and another stub attached to the south-west tower.
The curtain wall that ran alongside the River Trent was rebuilt in the 14th Century and is the wall that remains today.
It was about this time that the castle was again remodelled and in fact the new west curtain wall was realigned with its north end nearer to the river.
The new wall had two towers, one in the north-west corner and another in the middle and both with many sides and angles.
This wall would have housed many new buildings, such as a great hall used to conduct business. None of those buildings remain but their great windows are still seen in the wall.
The north-west tower was similar to the south-west tower of the 12th Century, with two middle floors, a basement containing a prison, and a guard room at the top.
The tower in the centre of the wall had two prisons.
Alterations to the castle in the 15th and 16th Centuries were limited to such things as the installation of fireplaces and window glass.
During the Reformation the castle reverted to the possession of the Crown.
In 1560 it was leased to Sir Francis Leeke and in 1581 to the Earl of Rutland.
After the Earl's death the castle passed to his son-in-law, Lord Burghley, who created such comfortable surroundings that in 1603, the new King, James I, stayed there.
The castle's popularity with royalty may have contributed to its downfall.
During the Civil War, 1642-46, Newark held out for the Royalist cause and the castle was garrisoned by Royalist troops until ordered to surrender by the King.
After the surrender, the townsfolk were ordered to demolish all siege works, including the castle.
Squatters moved into some parts of the building while other people stole stone and timber for use elsewhere.
Despite the sorry state of the castle, it remained in possession of the Crown from 1547 and, between 1845-8, it became the first monument to be restored at Government expense.
In 1887 the grounds were landscaped and opened in 1889 with the ruins seen as a romantic backdrop.
During this period there was further conservation work with wall tops capped with concrete and Tarmac.
In the late Eighties and early Nineties the north-west tower was given a new roof.
The grounds continue to be well used by local people and visitors and has been the venue for several concerts.
Landscaping work continues as the more formal gardens of the Victorian era are recreated.
There is still much that is not known about the history of Newark Castle, such as the exact locations of its northern defences.
Archaeological excavations in recent years have filled in many gaps, however, and dispelled some of the castle's myths such as whether King John did die in the south-west tower.
Summer digs have unearthed Saxon remains, including pottery fragments and animal bones.
A Saxon cemetery has also been uncovered, helping archeologists and historians to learn more about the origin and development of Newark.
The castle is open daily to visitors who may read about the castle story in the which is located in the castle grounds.