Hizbullah leader Sheikh Hassan Nasrallah promised hell for the IDF on the ground in southern Lebanon. He may not have heard of the Engineering Corps' elite Yael (Ibex) unit. Members of the unit, one of the most classified in the IDF, were the first soldiers to enter southern Lebanon during Operation Change of Direction, days before troops from the Golani Brigade set foot on the other side of the fence. Yael was responsible for clearing an access route for the infantrymen through the hundreds of explosive devices and mines planted there by Hizbullah. On Monday, the unit opened its doors to The Jerusalem Post. Using advanced technological warfare and well-honed senses, the soldiers of Yael have participated in dozens of operations into Lebanon since the fighting with Hizbullah erupted on July 12 following the abduction of two soldiers and deaths of eight more in a cross-border attack. Maj. Ido - the unit's commander - told the Post on Monday that Hizbullah had planted explosive devices along the border, made of high-quality explosives and put together with great expertise. "They build advanced and professional explosive devices," Ido said as his troops were preparing for the night's raid at a community along the northern border. "They are much more professional than the Palestinian bombs which we encounter in the Gaza Strip." In contrast to the infantry brigades which have operated in Lebanese villages a mere few kilometers from Israel, Yael, one of the other officers revealed, was responsible for the demolition of bridges in an effort to impair Hizbullah's mobility. The unit was also responsible for the demolition of several buildings in southern Lebanon, most of them used by Hizbullah. Why not just blow up the bridges and buildings by air? "Our demolitions are more precise and pinpoint and cause less collateral damage," Ido said, explaining that his unit inserted explosives into the buildings, bringing the structures down from inside. Candidates undergo a one-and-a-half year course before they are accepted as members of Yael. In addition to learning how to dismantle mines and demolish buildings, members of the unit are also trained in how to covertly enter enemy territory. As the unit that entered Lebanon first, that skill is what keeps the soldiers, who carry equipment weighing sometimes 70 kilograms, alive. "We know how to move quietly while carrying heavy equipment," Ido said. "Being quiet can sometimes save your life."