The integration of outdoor seating in urban areas near catacombs can significantly alter the microclimate of these underground spaces. By disrupting airflow patterns and modifying surface temperatures, seating arrangements may either enhance or hinder natural ventilation within catacombs. Studies suggest that strategically placed seating can create pressure differentials, drawing cooler air into subterranean passages during warmer months. Conversely, dense seating clusters may trap heat near entrances, exacerbating the urban heat island effect. The materials used for seating also play a crucial role—porous, reflective surfaces tend to mitigate temperature extremes compared to heat-absorbing materials. This interaction between surface-level urban design and underground environments presents unique challenges for preserving the delicate equilibrium of historic catacomb ecosystems while accommodating modern public spaces.