There are several areas in the US that were used to train bomber
pilots that have soem unexploded bombs. The land was federal property
at the time, and few records were kept. Some developer built a
subdivision on one such area years ago, and the Army Corp of Engineers
had to check the area for unexploded bombs, and other munitons.
They still have a drop zone in the Ocala National Forest where they
drop dummy bombs, and a couple morons were caught trying to sell some
they stole as scrap metal, last year.
USAF have a particularly bad reputation in the UK for not being able to
find a target and hit it reliably. They also used to prang widowmakers
into the East Anglian marshes with monotonous regularity. The SR-71s
were very impressive though on take off and final approach.
Even today the USAF are pretty sloppy about dropping munitions in
entirely the wrong place a long way from the Otterburn practice range:
http://news.bbc.co.uk/1/hi/england/suffolk/3389957.stm
In pre GPS days the US display team were notorious for being heard but
not seen at the small grass runway Barton Airshow near Manchester and on
one occasion were about to start their display lined up with the much
larger and busy Ringway civilian airport about 10 miles away.
http://www.pprune.org/archive/index.php/t-354110.html
I quote from an ATC of that era (this one a Woodford RAFA airshow):
The F 1/11 did its fast pass at Manchester instead of at the Woodford
airshow. I did my RT exam in 1978 with the controller who was on
'Manchester Approach' that day. He told me he saw the primary return
coming across the Pennines at several miles per 'paint', and soon
realised it was headed for Ringway instead of Woodford. It was, of
course, on the Woodford frequency so the Manchester controller picked up
his phone to advise Woodford of the situation. As he did so, he heard
the roar of its low pass past his tower!
It missed an approaching Vanguard east of Stockport, and a Viscount
climbing out over Knutsford, did a big 'U' turn, and went back east,
home and probably unaware of his mistake (until he landed at base!).
The USAF could often not find Barton - the RAF always did. Some US
display aircraft went fuel critical trying to find us, so never got to
the show, and one F 1/11 did one fast pass, turned left, and lost the
field. He never found it again before he had to go home due fuel critcality
Civilian aircraft like Concorde had no difficulty in finding either
Woodford or Barton airfields reliably every time. Concorde pilots had a
trick of coming in quietly and switching to full power and afterburners
about half way along the strip. Every car alarm went crazy.