Accessible by bike
Free parking next to the cache.
coach 300 to Dunakeszi Sportpálya or train to Dunakeszi Gyártelep
Roman fortress museum
It is a very interesting sight because you can see a ruin in a cellar of detached house. It is a privat museum so first you have to check in. Luckily there are some open days, too and you can see it without checking in on these days. link
Ruin was explored by builder during the construction of detached house. The owner started the digging and renewed the ruin wall. Next to the wall there is a showroom as well.
Emperor Valentinian had the fortress in the fourth century because Valentinian rebuilt and improved the fortifications along the frontiers (even building fortresses in enemy territory). Museum don’t have any regular opening hours!!! Free to visit in open days or groups can check in but they have to buy a supporting ticket (at least 10 up to 50 people).
There are a part of wall and a memorial tablet on the street. The Danube bank is very pleasurable for walking.
Another part of ruin is on the other side of the Danube on the Szentendre island. It is undiscovered by archaeologists yet.
You can find this page on the http://geocaching.hu/caches.geo?id=4229, too. It is the Hungarian geocaching website.