Dulles Expo Center

I’ve been to the Dulles Expo Center many times over the years for a number of different events — most notably the re-​occurring Sugar Loaf Crafts Festival.
The building is large enough to accommodate the event. Parking can be difficult at times. They might want to convert part of the parking lot into a parking garage so more spaces are available.
The restrooms are also in need of major retrofit and renovation.

As a vendor this place is ok. Building had sufficient space and ample parking, but food options are very limited and overpriced. Bathrooms are disgusting. I was appalled.

I’ve attended several types of shows at the Dulles Expo Center: Gem, Christmas, and Greenberg Train Show. The Expo Center now operates out of only one exhibit pavilion rather than the former two. All of the shows have been well organized and the large pavilion provides sufficient floor space for the vendors. Try going to a show that interests you. It is a main exposition center for the greater Washington, DC, region.
It is often easier to deal in cash at these shows, so bring cash with you. (There is an ATM on the premises). The shows are popular and parking is always at a premium. I recommend arriving early in the day. A snack bar is provided in the hall, but there are many restaurant choices in the immediate vicinity.

They have some good shows here. The Nation’s Gun Show and the Lego Show are packed every time they come here. Although this place gets crowded, it’s large enough inside that it doesn’t seem like it. I’ve never left complaining of too many people. The parking gets a little croeded, but as long as you’re willing to walk a little bit, there are spots available the farther you get from the building.