Found in Preston in 1793. It was interpreted in 1961 by A. Simons 1793, 3-couple set, longways Repeat dance three times.
Recording: trip_to_tunbridge-069-bn13mbt-11.mp3.zip
trip_to_tunbridge--0.mp3.zip
trip_to_tunbridge--010.mp3.zip

Video: http://dancevideos.childgrove.org/ecd/playford/248-trip-totunbridge
(3 couple, longways)

A1 1-8 1’s cast down the outside to the foot, “take a peek”, then
       dance back to the top.
A2 1-8 1’s dance down the center, then turn towards each other
       to face up, skip to the top, separate and cast around
       the 2’s (2’s pause, then lead up.)
B1 1-4 1’s pass R-shoulder, then R-hand turn 1st corner.
   5-8 1’s pass R-shoulder, then R-hand turn 2nd corner.
       1’s pass R-shoulder again, to end in middle place facing
       out (Others turn and face out to make two lines-of-3.)
B2 1-4 Lines-of-3 lead out a double and fall back, turning to
       face partner just at the end.
   5-8 2’s at the top 2-hand turn 1x. 1’s in middle place dance a
       long cast to bottom. 3’s in bottom place 2-hand turn
       moving up to middle place.

As someone born in Tunbridge Wells, I'd spell it “Tonbridge”. But that's because Tunbridge became Tonbridge in 1870.–NashJc 17:25, 21 March 2010 (EDT)