Abstract
Experimental methods of studying hypernuclear ground states and continuum states observed in the recoilless Lambda production are reviewed. These two types of hyper-nuclear states give the most direct information on the Lambda -nucleus interaction. The Lambda particle is a unique probe of the nucleus; it interacts strongly with the nucleus and is distinguishable from the nucleons. In light hypernuclei, gamma spectroscopy is a powerful tool in studying the bound excited states.