Recently I was in Iron Hill Park searching for locations to squeeze in a few more caches and this one was the most interesting spot I found.
Park in the main Iron Hill parking area near the dog park and head for the information signs and port-a-potties at the top of parking lot. Look for the yellow gate behind them. To the right is the trailhead for the dark blue blaze (blue/green) trail which skirts a very deep depression on your right--the remains of the old Whitaker Iron Mine. Continue on the blue blaze trail for 0.24 miles to reach the listed trail split. There are a few trail off-shoots, splits and junctions before reaching it. You will pass a post/trail off-shoot to the left. Keep going straight. Then another trail off-shoot to the right. Again keep going straight. Just up ahead the trail will split. Bear right and keep going straight past 2 minor trail junctions. You are now getting close to the listed trail split. Once there, you will see a green post. Bear left and stay on the blue/green trail for 100 feet or so until you run into a tree marked with a double blue blaze and green arrow on your right. Another trail will cross here but continue straight down the gully path until you reach the listed unmarked trail (UT) reference point. It is just past the pile of cut logs. Now you are only 0.16 miles from the cache. Turn right and follow this unmarked trail to within 80-90' of the cache. The cache container is small, thin, yellow flashlight (4"x 0.5" dia.). It does contain an extraction device for the log but it may be "useful to bring your own extraction tool as well". NOTE: The large deposits of iron ore in Iron Hill and the abundant tree cover causes satellite signals to bounce a bit so let your GPS adjust to the local conditions. If the signal is still jumpy you may have to use the hint. As of 6/14/15, ground zero has shifted some but the container is still reachable. This is a micro so don't forget to bring your own pen or pencil to sign the log. After finding the cache continue down the unmarked trail just a little bit. Once you are near N39_38.678/ W075_45.147 (before the trail bends to the right), do a straight bushwhack of 75-80 feet. Here you will be at the top of deep depression - the remains of the Keith Mines, another old iron mine. Follow the trail a little more to N39_38.710/W075_45.097. From here you can see the middle to lower end of the old mine. Overall this will be about a 1.0 mile round trip from the main parking area, but if you were to continue along the unmarked trail for 0.33 miles you will eventually run into the "Boulder Dam" cache [GC5W11D].
Warning: Mosquito/bug repellent may be required during the summer months. Also some days you may need to watch out for mountain bikers!
All 4 of the new caches are placed on the other side of the park. They can not be accessed from I-95 or 896, so please use the listed parking and plan accordingly. Once all of them are published you can make a 2 mile loop on both marked and unmarked trails to retrieve them and return to the main parking area. You can start with this cache then find the "Boulder Dam" cache, the "Black and Blue Bison in the Woods" cache [GC5W149], and finally the "Iron High Low" cache[GC5W02T]. Or start with the "Iron High Low" cache and go in reverse order.
Have fun and happy caching!
Congratulations to shorttripp for first-to-find!
Update as of 2/20/2020> I checked on this cache today. For this one I replaced the log sheet as it was full. Other than that the cache is in good shape.. I also noticed that some of the trail posts have been removed.