The flat, table-like summit of Morro São Jerônimo rises above the southern edge of the national park, affording spectacular 360° views of Chapada's rock formations, the Pantanal and the valleys below. It's an excellent and not particularly difficult day hike, though it is an 18km round-trip. Bring plenty of water and appropriate shoes.
You can opt to climb this as part of the two-day Travessia hike, which also includes the Circuito das Cachoeiras.
You must enter with a registered guide. Prices vary according to what you want; figure around R$200 per person. The webpage links to a list of guides.