When I visited Tilbury Fort, I found it an interesting experience with a few surprises. The fortifications themselves are impressive, and they offer great views of The Thames, Gravesend, and Tilbury. The Water Gate (ceremonial gate) is very grand, and the empty plinth was intended for a statue of Charles II, but even without it is is a great piece of architecture.
The fortifications date back to the time of Henry VIII, and underwent their first upgrade during the Spanish Armada scare of 1588. They played some role in the English Civil War, and following the Dutch raids in the post-Restoration period they were upgraded again to the star-bastioned fort of today. That was not the end, however, as the fort was used as a river defense as late as the Second World War.
The barracks, gun emplacements and bastions give a feel for the wide range of history the site has been involved in. 18th Century guns are backed up onto modern (WW2) gun positions, giving a feel of the changes.
On the day I attended there were reenacters on site as well. It was a great learning experience.
The ramparts provide for some great views of the Gravesend side opposite, including the Sikh Gurwara. There are also well maintained barracks, and an incredible moat system to check out.
The fort and the “seawall” also let you just watch the traffic on the river, and to get a feel of the past.