<![CDATA[Mathematics is often perceived by students as abstract and detached from everyday experience. Integrating cultural contexts through ethnomathematics can bridge this gap by connecting mathematical ideas to local heritage. This study explores the ethnomathematical potential of Petirtaan Jolotundo (Mojokerto, Indonesia) by identifying mathematical concepts embedded in its architectural elements and transforming these findings into structured indicators for contextual mathematics problems. Employing a qualitative exploratory design, data were collected through site observations, semi-structured interviews with relevant stakeholders (i.e. the site manager and one staff member with comprehensive knowledge of the site's historical background and structural features), and documentation (photographs and field notes). Data credibility was strengthened through triangulation across methods and sources. The analysis involved categorizing salient site elements—such as the gate, stairway, stone relief structures, and water spouts—and mapping their visual/structural features to mathematical concepts. The results indicate that the gate reflects dilation (scale relationships), the stairway illustrates slope/gradient, and the reliefs and water spouts exhibit line symmetry. These ethnomathematical findings were then translated into context-based problem indicators aligned with school mathematics topics (e.g. transformation geometry, slope, and symmetry), providing a culturally responsive resource for mathematics instruction. The study suggests that cultural heritage sites like Petirtaan Jolotundo can serve as meaningful contexts for developing contextual tasks and strengthening students’ mathematical understanding through locally grounded learning materials.]]>
