Bolognaで最も古い樹木はどれですか。

Bologna's monumental trees are documented through Italy's national register (the Alberi Monumentali d'Italia list, created under a 2013 law) and the Emilia-Romagna region's own parallel catalogue, together covering eight specimens within the city itself. Among those, the oldest with a precisely traceable planting is one of the large plane trees in the Parco della Montagnola, the city's first public park, laid out from 1805 under instructions passed down through Napoleonic administration and redesigned by the architect Giovanni Battista Martinetti. Several of the park's planes from that era survive today with trunks exceeding four metres around, roughly matching the age of a second Montagnola-era plane now standing alone in Piazza Minghetti a short walk away. A coast redwood in the Giardini Margherita, planted decades later as part of that park's own 19th century landscaping, is not far behind in size but carries no comparably precise date. The Montagnola park is free and open daily, a few minutes' walk from Bologna Centrale station.