  Large frame Ring laser gyroscopes, based on the Sagnac effect, are top
sensitivity instrumentation to measure angular velocity with respect to the
fixed stars. GINGER (Gyroscopes IN GEneral Relativity) project foresees the
construction of an array of three large dimension ring laser gyroscopes,
rigidly connected to the Earth. GINGER has the potentiality to measure general
relativity effects and Lorentz Violation in the gravity sector, once a
sensitivity of $10^{-9}$, or better, of the Earth rotation rate is obtained.
Being attached to the Earth crust, the array will also provide useful data for
geophysical investigation. For this purpose, it is at present under
construction as part of the multi-components observatory called Underground
Geophysics at Gran Sasso (UGSS). Sensitivity is the key point to determine the
relevance of this instrument for fundamental science. The most recent progress
in the sensitivity measurement, obtained on a ring laser prototype called
GINGERINO, indicates that GINGER should reach the level of 1 part in $10^{11}$
of the Earth rotation rate.
