Complex sentence: During the Great Moravian period, Devín was a center of a larger agglomeration, its defensive role was supported by smaller hill forts on Devínska Kobyla (Na pieskach, Nad lomom).
Split into simpler sentences: During the Great Moravian period, Devín was a center of a larger agglomeration. Its defensive role was supported by smaller hill forts on Devínska Kobyla (Na pieskach, Nad lomom).