Not all condemnation proceedings are the same. State laws differ on the number of hearings and the procedural structure of each, depending on the type of property in question or the intended use. Generally, a landowner may contest both the proposed taking and the amount of compensation offered. Ultimately, if administrative appeals fail, the landowner may petition in court, under the auspices of violation of constitutional rights.
Both sides may offer witness testimony and other evidence in support of their positions. Both sides may call attention to the fair market value (by expert testimony) of similar properties for comparison. Following court decision, appeals may take years, but generally does not stay the taking; if a landowner ultimately prevails on appeal, only money damages are generally available.