With a mass close to that of a gold atom, the top quark is the most massive, point-like, particle known to exist in nature. It plays a major role both in the experimental and theoretical frontiers. Experimentally, observation of top quarks is challenging, its signature is similar to that expected from new physics (NP) dynamics. The top was only very recently rediscovered at the LHC, an important milestone in the commissioning of the detectors. It is marking the beginning of the hunt for the unknown. Theoretically, the top quark is believed to be linked to electroweak symmetry breaking and the fine-tuning problem, probably the most fundamental questions in contemporary particle physics. We discuss how top physics form a portal to extra dimensions discovery and how it is searched for at the Tevatron-CDF and at the LHC experiments.