In 1828, the Principality of Monaco and the Kingdom of Piedmont-Sardinia established a physical border with 91 boundary stones, each numbered 1 to 91, running along the border from present-day Fontvieille to Menton-Garavan. Prior to 1848, the Principality of Monaco included the villages of Roquebrune, Monti, Garavan and Menton. Of the original 91 boundary stones only 12 remain: 6 within the Principality of Monaco, 3 in Roquebrune-Cap-Martin, and 3 in Menton. The boundary stones numbered 9, 12, 15, and 31 are located in Monaco. Another stone has been cast in concrete in the Sainte-Cécile area of Monaco thus rendering its number illegible. Stone number 55, originally located in Roquebrune, was given as a gift from the city of Roquebrune to the Principality of Monaco and is now located in Monaco's city hall. Stones numbered 56, 57, and 58 are located in Roquebrune. Stones numbered 62, 71, and 73 are located in Menton. All the boundary stones have three engraved sides: one side with their individual numbers (1 to 91), one side with the letter "M" indicating Monaco's territory, and one side with a cross (+) indicating the Kingdom of Piedmont-Sardinia's territory. The cross represents the coat of arms of the House of Savoy, rulers of Piedmont-Sardinia.