<p><b>PURPOSE: </b>We describe the sample, design, and procedures for the Community and Surrounding Areas Study (CASAS), an ancillary to the Hispanic Community Health Study/Study of Latinos (HCHS/SOL). The aim of SOL CASAS was to test an ecological model of macro- and micro-neighborhood environment factors, intermediate behavioral (physical activity) and psychosocial (e.g., depression and stress) mechanisms, and changes in cardiometabolic health in Hispanics/Latinos.</p><p><b>METHODS: </b>Between 2015 and 2017, approximately 6 years after the HCHS/SOL baseline (2008-2011), 1776 San Diego HCHS/SOL participants enrolled in SOL CASAS and completed a repeat physical activity assessment. Participants' residential addresses were geoprocessed, and macroenvironmental features of the home were derived from publicly available data concurrent with the HCHS/SOL baseline and Visit 2 (2014-2017). Microscale environmental attributes were coded for 943 unique routes for 1684 participants, with a validated observational tool, concurrent with Visit 2, for SOL CASAS participants only.</p><p><b>RESULTS: </b>Of 2520 HCHS/SOL participants approached, 70.5% enrolled (mean age 55.3 years; 94% Mexican; 67.5% female). Accelerometer adherence (three or more days with at least 10 hours wear time) was outstanding (94%).</p><p><b>CONCLUSIONS: </b>With its more comprehensive ecological model and well-characterized Hispanic/Latino population, SOL CASAS will advance the science concerning the contribution of neighborhood factors to cardiometabolic health.</p>