Dan is probably right about the water pump, and if he is right the coolant wil be seeping,(or gushing) from the seal around the water pump shaft. But check all the hoses that go in and out of it, plus the little bypass hose that is about 5 or 6 inches long tucked down under all that stuff. You have the lower radiator hose, and the two heater hoses, which can develope leaks from such silly,simple things as a loose hose clamp. Also you can get a leak from a bad seal on the thermostat housing gasket. If you have access to a cooling system pressure pump, pump it up to 13 pounds, and let it sit, while you look and listen. You should see and hear where things are leaking from.
Less likely, but still possible is sometimes the front exhaust manifold stud, which is right next to the thermostat housing can leak, and that would also dribble down the front timing chain cover. Even if you have not taken it out, but have simply loosened it by accident, thinking your wrench was on the thermostat housing bolt, and then retightened, you could possibly break the thread sealant enough to start something there. Ask me how I know about that one.
Sam
Just check the hose clamps if you can get to them.