1. THE  ČABRANKA
(from Čabar to Osilnica, alt 600 m - 290 m)
The river is embraced by a picturesque valley with magnificent steep banks and precipitous cliffs. The Čabranka springs from an exurgence under the Podplanina village, then passes the Draga village through the Dragarska dolina valley to come to the Loški Potok village. After some kilometers the river bites into the high cliffs of the Žurgarska and Taborska stena mountains, passes small settlements Pungert, Črni Potok, Žurge, Papeži, Belica (in the past a stronghold against the Turks) Bezgarji, Bezgovica Strojiči and shortly after that falls into the Kolpa.
The whole area of the Čabranka, including the Croatian part, was part of Carniola in the past. In the l7th century it came under the rule of Croatian Frankopan, but was nevertheless settled by the Kočevje Germans as well as Slovenes from Bohinj, Železniki, Idrija.
2. THE  UPPER  CANYON  OF THE  KOLPA
(from Osilnica to Grivac, passing under the Borovška gora and Kuželjska stena mountains; 287 m - 222 m; gradient 4.4%)
The monthly mean flow at Osilnica is 22.6 m3/s; it is lowest in August (7.9 m3/s) and highest in November (37.5 m3/s). It is exactly here, at the confluence with the Čabranka, that the Kolpa reaches the Slovene bor- der and the valley widens to several hundred meters to provide space for bigger settlements on both sides of the border. On the Slovene side we have Osilnica, the biggest town in the area with the old parish of St. Peter and St. Paul, next to Osilnica there is Sela and above it the villages Križmani, Zgornji Čačič, Spodnji Čačič, Padovo near Osilnica, and a bit further downstream Malinišče. Another slightly bigger town is Ribjek with the old church of St. 6iles, followed by Ložec, which is surrounded by the following mountains: Loška stena (alt. 876 m), Firstov rep (alt. 1002 m), and Mož and Baba (alt. 1125 m). The latter two are lone-standing rocky columns on the edge of the Borovniška gora mountain, a karstic plateau boasting a virgin forrest, home of the chamois and alpine flora. Without a doubt, owing to the gorgeous Jurassic and Cretaceous cliffs on the Slovene side, this is the most beautiful and imposing part of the valley with the river featuring numerous rapids. The line of rocky peaks and cliffs continues with the Krokar (alt. 1122 m), Krempa (alt. 944 m), Borič (alt. 909 m), Kapič (alt. 905 m) and Kuželjska stena (alt. 874 m); below them the following settlements are crowded: Grintovec near Osilnica, Bosljiva Loka with the subsidiary church of St. Vitus, Mirtoviči, featuring the distinctive hill called Orlovski vrh with the rock-sheltered cave Velika luknja, and Srobotnik on the Kolpa. Before we reach Srobotnik, on a cut-off meander of the Kolpa, there is the lonely St. Ann's church.
3. Kostel
(from Petrina to Kostel, alt. 222 m - 207 m)
 

The Kostel is a beautiful wide valley, resembling a natural amphitheater caught between high, steep slopes and somewhere even vertical cliffs of Jurassic and Cretaceous limestone. The Slovene side has almost 30 small settlements situated around the ancient parochial center Fara; it is right here that the priests of the primordial parish of Ribnica gathered as early as in the 14th century, while the whole area was ruled the by the Counts of the Kostel castle.

Where the largest right-hand tributary Kupica (Slovene: Kolpica) flows into the Kolpa, on the Croatian bank there is the old parochial and market center Brod. Somewhat bigger Slovene towns in the vally area: Petrina at the border pass over the Kolpa, the villages of Pirče, Vas and Fara, the latter with the parochial church of St. Mary, and Slavski laz with a subsidiary of the Holy Trinity. This end of the valley is dominated by the magnificent Kostel castle, in the past also a fortified market-town, overlooking the steep banks of the Kolpa.
4.  THE  CENTRAL  CANYON
(from Gorenja Žaga to Spodnja Bilpa and further on to Dol, alt. 207 m - 187 m)
 

This is a genuine river canyon, cut in the Jurassic and Cretaceous limestone strata, the width of the river-bed not exceeding 100 meters and the steep, partly precipitous banks reaching 300-350 meters high. Only a couple of lonely houses, water-mills, forges and small villages indicate the continuous communication between the river and the higher placed settlements, in the past mostly inhabitated by the Kočevje Germans. Near the entrance to the canyon we find Dolenja Žaga, Gorenja Žaga and the boiling spring cave Kotnica (water supplied from the Kočevska Reka region), followed by Lobič, Žlebe, Grgelj and Spodnja Bilpa, featuring an imposing exurgence and rock-sheltered caves under a vertical cliff.

Where the canyon spreads a bit wider we find the village Laze pri Predgradu with a nice subsidiary of St. Vitus; after that the canyon gets narrower again to finally widen a bit just downstream of Stari Trg ob Kolpi at the village Dol, the primordial administrative and ecclesiastical center on the state border.
5.  THE  LOWER  CANYON
(from Stari Trg ob Kolpi to Damelj pod Poljansko goro; alt 187 m - 167 m)
The beginning part of this section is a gorge mostly several hundred meters wide and here we find some bigger settlements like Prelesje, Kot ob Kolpi, Sodevci, Dečina, Gorenji in Dolenji Radenci. The mean annual flow at this point is 54.8 m3/s, being lowest in August (23.4 m3/s) and highest in November (87.6 m3/s). Shortly after that the valley gets narrow again, but thesteep banks under the villages Špeharji and Daljnje Njive and the Sebetih hill (alt. 475 m) are lower now and no longer precipitous. The Croatian bank features the famous Zrinjski grad castle at Severin na Kupi; a bit further downstream on the Slovene side there is the karstic valley Suha dolina (also called Draga) opening up to the north. Following is the meander round the Jelenča glava hill (alt. 389 m), the last part of the Poljanska gora mountain.
6.  THE  UPPER  STREAM  IN  BELA KRAJINA
(from Vukovci, passing Vinica, to Žuniči; alt. 167 m - 150 m)
All the way from Vukovci towards north-east and past Učakovci the Kolpa's river-bed gradually becomes wider and shallower to reach the greatest width at Vinica, known as the primeval natural strategic passage across the river from Bela Krajina to the Gorski Kotar range. The settlement itself has an llth century forti- fied castle and the pilgrims' church of St. Mary on the Žeželj hill (alt. 334 m), as well as the parish of St. Cross, dating back as far as the l3th century. From the l6th to the 18th century the whole area was populated with "uskoki", refugees tleeing from Turkish raids. Soon after that, under the villages Zilje and Vidine, the river gets narrower again and at the Preloka parish it is widened to reach Žuniči. After several kilometers- the river-bed is narrowed again and in a sharp bend the river turns to the north-west.
7.  THE  LOWER  STREAM  IN  BELA KRAJINA
(from Miliči to Griblje; alt. 150 m -136 m)

The lower stream in many ways resembles the upper, except that it is even wider under the old settlement of the "uskoki" Marindol and the Adlešiči parish: the bot- tom of the valley is 200 - 300 meters wide and the steep banks are about 50 - 70 meters high. The old Pobrežje castle is the strategic passage across the river, followed by the villages Dolenjci, Fučkovci and Dragoši. The banks are gradually becoming lower, reaching 10 - 20 meters of height.

8.  THE  FLATS'  STREAM
(from Griblje to Radoviči; alt. 136 m - 132 m)
There is no trace of the shallow karst, the river runs through Quartenary flooding flats from the villages Griblje and Krasinec to Podzemelj, Zemelj and Otok. Close to the left bank you will find the attractive scenic- view hill Kučar (alt. 222 m), a prehistoric post. The only tributary of Bela Krajina, the lahinja, falls into the Kolpa at the village Primostek; the following kilometer of the valley is narrow, because the Kolpa passes an area of shallow karst. After that, at Log, it is opened into the Metlika flats and passes Križevska vas and Metlika.
9.  THE  BOŽAKOVO  VALLEY
(alt 132 m - 124 m)
The Božakovska dolina is the last narrow passage of the Kolpa before it enters the extensive Croatian flats with meanders and swamps of the Panonia. Cretaceous strata of limestone facing south provided the last barrier for the Kolpa to cut through, featuring a narrow river-bed, with some 50 meters high banks under the village Božakovo. Through this passage run: the ancient traftic connection between the Carniola and Karlovac. Average annual flow of the river at this point is 76.3 m3, being lowest in July (34.6 m3) and highest in December (108.7 m3).