castles in Belgium

"My hope is to explore some castles that are mostly in their original state instead of modernized, reconstructed, etc." Other than a few ruins in the Ardennes, I can't think of a single castle in Belgium that hasn't undergone some kind of restoration or modernization. But if you're looking for heavily restored castles that seem like they're in something like their original state, here's a few ideas:

Kasteel van Horst, east of Leuven. It has undergone quite a bit of restoration, but with an eye to preserving it's form from the 16th-17th centuries. Very hard to reach via public transportation, so a car will come in handy.

Kasteel van Beersel, in the Brussels suburb of the same name. The keep is ruined, but most of the rest of the form of the castle still remains, including it's impressive towers. When I visited last spring, there was a lot of scaffolding and restoration work. Knowing how long these things usually take, I would imagine work remains on-going. If you don't want to drive, you can easily take a commuter train from Brussels. The castle grounds sit adjacent to the rail stop.

Het Gravensteen, smack in the middle of Gent. Heavily restored, but it looks like it came straight out of the 14th century.

Het Steen, Antwerp. A small fragment of what was once a much larger castle guarding the river Scheldt, it now houses a maritime museum.

Landcommanderij Alden Biesen, near Bilzen. Relatively unmodernized since the 18th century, but not exactly medieval, if that's what you're looking for. The property also has a large garden. If you choose to visit, the car will come in handy. And if you're in this part of Belgium and you have an eye for history, check out the open air folk museum at Domein Bokrijk between Hasselt and Genk, which is one of the best I've seen in Europe. The advertised kasteel here, though, is more of a mansion, see below.

One slightly confusing detail. Kasteel, the Dutch cognate for the English word castle, has a much broader meaning. It is often applied to any stately home, whereas in English, we might further specify the same building as castle, palace, mansion or even large farm house. So, if you read a lot of the tourist literature that gets directly translated from Dutch, it may describe something as a "castle" that to you looks more like one of the old estate homes you would expect to find in the Main Line.

Thank you for the advice and explanations. I'm open for more suggestions on this topic.

It's certainly spruced up, but it's very easy to get to the exterior of Castle at the center of Turnhout, now used as a private insurance company office. The plus is that the town has a superb Begijnhof, with a museum, if your plans include a few of them.

You might also consider expanding your exterior visits to some of the many ruined (and generally unimproved) defense forts around Belgium. One I've tried and failed to get into is Fort 5-Mortsel in Antwerp, which might be open only on Sundays(??) for a few hours. The Mortsel tram line ends nearby, but it's still a hike into the park.

Alas, the Antwerp Maritime Museum has moved to one floor of the MAS. I think you'll find Het Steen locked up while the city looks for a low-cost way to open it again. But you can walk the ramparts and look at a bronze tablet commemorating the WW II liberation of the city.

You don't say how old the castle has to be. It's really a little-known (but fully set up as an educational destination) Nazi era site (and a scary one at that): Fort Breendonk. Dedicated parking lot, but not as easy by train, then bus.

Breendonk is outside Mechelen, where you can walk around the very same (more or less) garden where Charles Quint played as a child. There's not much castle left, but the town has a nice medieval square, and the ground-plan "ghost" of its Begijnhof.

I would seriously suggest that you consider scheduling your trip for the next time the Flemish area has "Open Monument Day" (Openmonumentendag), typically the second weekend of September. The actual sites aren't announced in time to buy air tickets at the last minute (!), and I can't promise that any castles will be open. But it's a rare chance to see old buildings that aren't normally open to the public. Just an idea.

You did say castles, but you might also want to include the Open-Air [historic building] Museum in Bokrijk, which is comprehensive and excellent.

Open Monument Day and its sister projects throughout the EU including London Open House, big programs in the Netherlands and France, and Italy used to until it ran out of money, is a fabulous program...

The link to the Flemish one is at http://www.openmonumenten.be/and most programs are on the same weekend. London is always a week different from the rest of England.

Now, if you're willing to consider citadels, as opposed to castles, and to expand into Wallonia, you can easily check out Namur's citadel. If you're in Namur with a car, you may want to consider driving a little further up the Maas river for a quick visit to the pretty little town of Dinant. It also has a citadel, although the tour isn't particularly interesting. And if you're in the general area, you may as well venture a little further south to see Château de Lavaux-Saint-Anne.