Δ
A series of caches based on the letters of the Greek Alphabet.
There are 24 letters in the Greek alphabet. They've been around
since around 850BC. The Greek alphabet is itself derived from the
Phoenician alphabet. The Greek alphabet has itself been the basis
of other alphabets including the Latin alphabet.
Modern Greek letters today, are used for symbols in mathematics
and science. amongst other things.
"Delta" is the 4th letter of the Greek
alphabet. It is derived from the Semitic word for fish or door.
Delta represents the angle that subtends the
arc of a circle in surveying. In astronomy it is the distance to
Earth, measured in astronomical units. .
The cache is a small lock and lock box placed at ground
level.