Complex sentence: Sentinum was an ancient town of le Marche, Italy, lying a kilometre to the east of the modern town of Sassoferrato, in the low ground; its ruins were identified in 1890 and published by T. Buccolini.
Split into simpler sentences: Sentinum was an ancient town of currently located in the Marche region in Italy, lying a kilometre in the low ground at the east of the existing town of Sassoferrato. Its ruins were identified in 1890 and published by T. Buccolini.