Start with the basics of the location: photograph what immediately catches your eye. In a historic, decaying building, strong subjects often include architecture, texture, peeling paint, rust, old furniture, shadows, and graphic lines such as strong verticals and horizontals.

A prison interior will likely be dark, so light is the main challenge. Use ambient light as much as possible, and if flash is allowed, a diffused or bounced flash can help lift dark areas without making the scene look artificial. Don’t overdo it. A tripod is useful for static scenes, but added light may be more helpful in some spaces.

Look for framing, contrast between old and new, and high-contrast scenes that may work well in black and white. If you know how, HDR can help with difficult interior/exterior brightness differences.

Since you’ll be carrying limited gear, avoid constant lens swapping. Spend some time with one lens, then switch and work differently with the other. If possible, review images of the location beforehand to get ideas for angles and subjects.