[dem,lat,long]=readSRTM('TUNGURAHUA',170,170);

figure(1)
axis equal
cs = contourf(long,lat,dem,15); clabel(cs)
hold on
plot(-78.48759,-1.43428,'r*')
text(-78.48759,-1.43428,'  Cusúa')
plot(-78.44430,-1.36512,'r*')
text(-78.44430,-1.36512,'  Chontilla')
xlabel('Longitude')
ylabel('Latitude')