The Phipps Tunnel was built under Highland Street in Holliston on
the Milford Branch of the Boston & Albany Railroad. This rail
line originally ran from Milford to Framingham, passing through
Rocky Hill, Braggville, Metcalfs, Holliston, East Holliston, and
Whitneys.
There was commuter rail service from Milford to Boston until the
late 50's. Freight service continued until the early 80's when the
line was abandoned. The rails have been pulled up in preparation of
developing the branch into a bike path.
Some historic photos of the railroad in Holliston may be found
here:Holliston
Trails Website Note the photo of the mudslide near the tunnel.
It still sometimes gets very muddy near the cache today!
The cache is a match container placed near the tunnel. You can
access the cache from Highland Street if you're willing to deal
with a little poison ivy and a scramble up and down a fairly steep
slope. You may also park near N42 11.082 W071 26.399 and take the
short walk in along the old railroad grade.