The low internal noise of modern broadband seismic sensors coupled with the high-resolution of modern dataloggers has revealed significant sources of seismic noise which were not readily apparent on records obtained from previous generations of sensors and dataloggers. The two most significant noise sources, which ultimately determine the performance of a broadband seismic station, installed in an otherwise ideal location, are the reaction of the seismic pier to temperature and barometric changes and the thermal stability of the seismic sensor. An ideal seismic pier affects neither the response of the earth nor of the seismometer and construction of such a pier is contrary to traditional concrete construction practice. Substantial thermal insulation of both the broadband seismometer and the pier is necesary to attain the low-frequency (<10 mHz) performance of which the sensor is capable. These guidelines describe the construction of the seismic pier, the application of thermal insulation to the pier and broadband seismometer, and, as an example, the installation of a broadbamd station on the Farallon Islands. After installation, routine monitoring of the performance of the broadband instrumentation is essential to rapidly detect malfunctions.