Troja Basin
Troja Basin
This term applies to a widely opened valley of the Vltava of East-West direction in the northern part of Prague area proceeding approximately from the Bílá Skála (White Rock) below the Bulovka to the rocks in Podhoří. In the North it is bordered by high, locally steep and rocky slopes below Bohnice and Kobylisy, in the South by higher terraces of the large Vltava meander with the Stromovka park underneath. It includes also the broad fluvial plain of the Vltava accommodating the major part of Stromovka, the Troja (Imperial) Island and the broad strip of the fluvial plain from the Troja Bridge to Podhoří. The lowest point is theVltava bank in Podhoří with an elevation of 176 m, the highest point the lydite knob Vysoká Skála (High Rock) with an elevation of 314 m above sea level. In the framework of Prague it is a valuable landscape with preserved parts of the initial fluvial plane of the Vltava, rocky formations, often covered with ample rocky steppe vegetation as well as parks of a tradition of long standing and some facilities of importance for natural sciences (in the first place theZoological Garden and the more recent Prague BotanicalGarden). Apart from areas converted into gardens the latter includes also some important protected areas, such as the rocks in Podhoří or the Salabka. The territory is not disturbed by any major industrial enterprises or busy highways. The houses are low-rise and partly dispersed, as a result of which the area offers opportunities for suburban recreation.
Troja Basin
The slopes and rocky cliffs bordering the Troja Basin in the North consist of shales in the West and of greywackes of the Kralupy-Zbraslav group of the Proterozoic, cropping out also on the left river bank on the Baba and the Podbabské Skály rocks. Along the northern margin they contain minor lydite intercalations forming the knobs of the Vysoká Skála (High Rock) and the Vavrouška. In the margins of Stromovka and Bubeneč station as well as in the eastern part of northern slopes there are outcrops of shales and sandstones of the lower strata of Ordovician formation, comprising the intercalations of hard Skalka and Řevnice quartzite's, once extracted on the Jablonka and the Bílá Skála (WhiteRock) below the Bulovka. In the northern margin also the remainders of Cretaceous sediments have been preserved,cropping out near the Vysoká Skála (High Rock), at the Okrouhlík and elsewhere as well as the Pliocene gravels and covers. The lower steps are covered with Quaternary gravelsands of diverse origin, covered by thick loess series in the western part. Of considerable extent are also the fluvial plain deposits. The soils show a variegated development ranging from chernozems on loesses over different variants of brown soils and rankers on the bedrock to the aluvial plain soils and fills of old river arms within the fluvial plain. At present the Vltava river bed is straight, but in the past the river formed free meanders in the Troja Basin the remainder of which is the still existing Malá Říčka (Little River) in the margin of the Stromovka park.
At present the Troja Basin is an important refugium of minor fauna in the Prague area the buildings of which are surrounding it on all sides. There are numerous bird nesting sites including old trees and dense brushwood. There are roebucks and minor carnivores. The slopes facing the South are the habitat of rare species of xerothermal insects, the rocks of the Podhoří and the Podbabské Skály host molluscs. In recent years some riverine-wood animals have returned to the plains of the Vltava, such as Urticiola umbrosus from the number of snails. Remarkable is also the occurrence of the cormorant on the Vltava.
Forests in the initial meaning of the term have not been preserved in the Troja Valley. Until recently they consisted only of loose woods along the river, consisting mostly of poplars. Only after the Second World War extensive wood planting took place; at present these woods are managed as special-purpose suburban woods.
Similarly as the whole northwestern part of Prague the Troja Basin forms part of the ancient settlement area inhabited and managed by man since the very beginnings of agriculture in the Neolithic. The remainders of their material culture can be found on numerous sites. Special mention should be made of the hillfort Farka above the Podhoří. Later on suburban settlements developed in the form of numerous solitary farms the names of which have been preserved to our day. It was the time of orchards and vineyards. The conspicuous building of the former wine press, Sklenářka, often considered as the executioner’s house, is worth particular mentioning. At present the buildings are mostly villas and single family houses. Fortunately, the mass-scale panel housing estates are situated beyond the upper edge of the basin.
At present the Troja Basin forms a sort of a natural oasis within the city boundaries. Industry was represented there by minor enterprises only which no longer operate. The basin is traversed by the main railway line to Děčín and on to Germany. The Vltava has been canalized and provided with a navigation channel which modifies the outline of the Troja (Imperial) Island and cuts off the former meander of theVltava, the Little River. In the eastern part the fluvial plane was modified with diverse fills and other interventions and has lost entirely its natural character. The waste water treatment plant in the Imperial Island should be liquidated in the future.
At present the Troja Basin is a harmonious landscape with a high proportion of greenery in which natural areas alternate with parks and suburban woods framing the Zoological Garden and the Botanical Garden. The Vltava, bordered with secondary meadows, forms a significant landscape element. The basin represents a quiet area of high aesthetic value balancing the negative effects of adjacent built -up territory.
One of the most valuable components of the Troja Basin is the Zoological Garden
with the new Botanical Garden on the upper left.
The Troja Castle with its French garden is situated in the centre.
View of the Troja Basin from the north.