A little farther on the colour of the soil begins to undergo a transformation, and soon the red sandstone--the colour that is typical of the same, as well as the more northern, latitudes in the surrounding republics--is stretching everywhere to join with the green in dominating the landscape. A few more wayside stations, and then Rivera and the Brazilian frontier are drawing near, while the mountain ranges that mark the Brazilian territory are already in sight. Rivera is a town of no little local importance, small though its extent may be as it nestles in a hollow in the midst of the hills. The soft pink of its buildings and the red of its roads and hillsides contrast delightfully with the green foliage and brilliant flowers with which the spot is so liberally endowed. Rivera, moreover, is a place that can lay claim to some quite notable characteristics of its own. It possesses, for instance, a magnificent avenue, the Sarandi, that stretches for over a mile, shaded by trees for all its length, from off the central portion of which lies the pretty little plaza. [Illustration: FRONTIER STONE AT RIVERA.] [Illustration: TUNNEL AT BAÑADA DE ROCHA. To face p. 192.] The best view of both the town and of the surrounding country is to be obtained from the solitary hill near by that marks the boundary between the two republics, and that bears upon its summit an old and battered boundary-stone. Viewed from here the panorama is fascinating. To the north, and immediately below, lies Santa Ana, the Brazilian sister-township of Rivera, that sends out its buildings almost to join walls with those of the Uruguayan. Santa Ana itself presents a picturesque enough prospect with its white houses and luxuriant gardens, its wide, unpaved, shadeless streets, its rambling barracks, and its red-bricked bullring. As a background to this bright, sunlit picture, and one that throws it into strong relief, rise range upon range of the dark hills with their shaven summits, starting up abruptly in the first instance from the confines of the town itself, and fading away gradually into the misty distance of the province of Rio Grande. Skirting the base of the hill to the east is a short avenue devoid of buildings that serves as the frontier line, and marks with no little emphasis where one town ends and the other begins. The significance of the spot is accentuated by the sight of the sentry-boxes of the frontier guards and custom officials. To the south, reclining in its own hollow, lies Rivera, with its shady avenues and its conspicuous round-towered church.