Entrance fee is $11 for trailer and two horses. There is a lot specifically for trailer parking with picnic tables, hitching posts, porta-jon and water for giving your horses water. The park has multi-use trails, about 12 miles are multi-use with 2-3 miles strictly for hiking and bike riding. The trails range from Easy to Moderate, some rocky areas and muddy areas if we have had some rain and one bridge crossing. The main trails are Sawtooth, Glenora and Big Woods which are mostly dirt with rocky areas mainly at water crossings. This circuit on horseback at a walk will take you roughly a little over an hour to ride. Mill Pond and Pigeon Run Trail has a few places with steep rocky hills, one particularly hilly area runs along the power lines and Pigeon Run has an area that is along the roadway back to the parking lot. There are several trails off Glenora and Big Woods trails that are very nice, one is Cedar Run Trail which has a nice picnic area with a hitching post, picnic table and bench and a place to take your horse into the water. Another is the Smoke House Exhibit which is mostly grassy with a trail that takes you to the water where you can take your horse into the water also. Gold Hill Trail is off Pigeon Run Trail and is the most rural trail in this trail system. It starts by running along the power lines and then goes off into the woods. It is rockier than the rest but is a nice quiet trail to ride. If you rode all the trails it would take you roughly 4 hours at a walk. There are plenty of places on these trails for you to safely canter, trot or job your horse. All the trails can be ridden either way, none of them are one way only trails. You can get a map at the gate and the trails are clearly marked with trail markers and distance. Every bike rider, hiker and horseback rider I have encountered on these trails has been very nice and courteous. I have not had a bad experience at Lake Anna and have been riding these trails for more than 10 years.