If you're brave you'll do this one at 10am on a Monday morning when they test the alarm...
For those that don't know, Broadmoor Hospital is a high-security psychiatric hospital in Crowthorne and houses some very famous inmates. The siren is there to warn local residents of any escapes and it is tested every week on a Monday morning at 10am. It can be rather loud.
Note, there is a stream alongside the cache, so please take care when retrieving the cache.
