Very large and fragile atoms may be produced by exciting normal atoms with light or by collisions with other atomic particles. Atoms as large as 10−6m are now routinely produced in the laboratory and their properties studied. In this review some of the simpler experimental methods available for the production and detection of such atoms are described including tunable dye laser-excitation and field ionization. A few recent experiments which illustrate the collision properties and the effects of electric and magnetic fields are also described. The relevance of highly excited atoms in other areas of research including radioastronomy and isotope separation are discussed.