diff --git a/CRiSp.Rproj b/CRiSp.Rproj
index 69fafd4..c076ae9 100644
--- a/CRiSp.Rproj
+++ b/CRiSp.Rproj
@@ -18,5 +18,5 @@ LineEndingConversion: Posix
 
 BuildType: Package
 PackageUseDevtools: Yes
-PackageInstallArgs: --no-multiarch --with-keep.source
+PackageInstallArgs: --no-multiarch --with-keep.source --install-tests
 PackageRoxygenize: rd,collate,namespace
diff --git a/tests/testthat/test-valley.R b/tests/testthat/test-valley.R
new file mode 100644
index 0000000..12ca12c
--- /dev/null
+++ b/tests/testthat/test-valley.R
@@ -0,0 +1,50 @@
+bb <- bucharest_osm$bb
+asset_urls <- c(paste0("s3://copernicus-dem-30m/",
+                       "Copernicus_DSM_COG_10_N44_00_E026_00_DEM/",
+                       "Copernicus_DSM_COG_10_N44_00_E026_00_DEM.tif"),
+                paste0("s3://copernicus-dem-30m/",
+                       "Copernicus_DSM_COG_10_N44_00_E025_00_DEM/",
+                       "Copernicus_DSM_COG_10_N44_00_E025_00_DEM.tif"))
+
+test_that("STAC asset urls are correctly retrieved", {
+  skip_on_ci()
+
+  ep <- "https://earth-search.aws.element84.com/v1"
+  col <- "cop-dem-glo-30"
+
+  asset_urls_retrieved <- get_stac_asset_urls(bb, endpoint = ep,
+                                              collection = col)
+  asset_urls_retrieved_default <- get_stac_asset_urls(bb)
+  expected_asset_urls <- asset_urls
+
+  expect_equal(expected_asset_urls, asset_urls_retrieved)
+  expect_equal(expected_asset_urls, asset_urls_retrieved_default)
+})
+
+test_that("raster data are correctly retrieved and merged", {
+  skip_on_ci()
+
+  dem <- load_raster(bb, asset_urls) |> CRiSp::reproject(32635)
+  expected_dem <- terra::unwrap(bucharest_dem)
+
+  expect_equal(terra::values(dem), terra::values(expected_dem))
+  expect_equal(terra::crs(dem), terra::crs(expected_dem))
+  expect_true(all.equal(terra::ext(dem), terra::ext(expected_dem),
+                        tolerance = 1e-4))
+})
+
+test_that("valley polygon is correctly constructed", {
+  dem <- terra::unwrap(bucharest_dem)
+  river <- bucharest_osm$river_surface
+  crs <- "epsg:32635"
+
+  valley <- get_valley(dem, river, crs)
+  expected_valley <- sf::st_read("./testdata/expected_valley.gpkg",
+                                 quiet = TRUE) |>
+    sf::st_as_sfc()
+
+  valley <- st_set_precision(valley, 1e-06)
+  expected_valley <- st_set_precision(expected_valley, 1e-06)
+  expect_true(sf::st_equals_exact(valley, expected_valley,
+                                  par = 1.e-4, sparse = FALSE))
+})
diff --git a/tests/testthat/testdata/expected_valley.gpkg b/tests/testthat/testdata/expected_valley.gpkg
new file mode 100644
index 0000000..d285245
Binary files /dev/null and b/tests/testthat/testdata/expected_valley.gpkg differ
diff --git a/tests/testthat/testdata/generate_valley.R b/tests/testthat/testdata/generate_valley.R
new file mode 100644
index 0000000..79bbaac
--- /dev/null
+++ b/tests/testthat/testdata/generate_valley.R
@@ -0,0 +1,8 @@
+dem <- terra::unwrap(CRiSp::bucharest_dem)
+river <- CRiSp::bucharest_osm$river_surface
+crs <- "epsg:32635"
+
+valley <- CRiSp::get_valley(dem, river, crs)
+
+filepath <- testthat::test_path("testdata", "expected_valley.gpkg")
+sf::st_write(valley, filepath, append = FALSE, quiet = TRUE)