Barrier put around Lima old resistance capital once (8)

I haven't cracked this one yet — but the brilliant team at Fifteensquared have:

FENCE (a barrier), around L (Lima in the radio alphabet) + O (abbreviation for old) + R (abbreviation for electrical resistance). City in Tuscany, Italy; according to Wikipedia it was the capital of the Kingdom of Italy for about six years in the 19th century.