If you have 2-3 hours to spend in Falkirk, there are several things you can do:
1. Visit the Falkirk Wheel - it is an engineering marvel that takes boats from the Union Canal to the Forth and Clyde Canal. You can take a boat tour or just watch it in action from the viewing platform. It will take around 1-2 hours, including travel time.
2. Explore the Callendar House and Park - it is a historic house with beautiful gardens and a museum. You can learn about the history of the area and enjoy a relaxing walk in the park. It will take around 1-2 hours.
3. Walk along the Antonine Wall - it is a UNESCO World Heritage Site that is a part of the Roman frontier. You can see the remains of the wall and the fortifications and enjoy the scenic views. It will take around 1-2 hours.
4. Visit the Kelpies - they are two giant horse sculptures that are a tribute to Scotland's equine heritage. You can take a guided tour or just see them from a distance. It will take around 1 hour.
Overall, these are some of the things you can do in Falkirk if you have 2-3 hours to spend. Choose the one that interests you the most and enjoy your time in the town!